An unusual musical instrument that combines keyboard and cellos has seen the light of day some 500 years after the Renaissance superman conceived it.
Leonardo's viola organista has come to life through the passion of Polish pianist Slawomir Zubrzycki, who has played a lavishly designed version of it in concert.
Zubrzycki produced the mechanically bowed keyboard, which resembles a bowed clavier, based on a sketch and notes in Leonardo's Codex Atlanticus, a collection of manuscripts covering miscellaneous subjects that is dated 1478 to 1519.
There's no evidence to suggest Leonardo ever built his viola organista, but Zubrzycki's version of it, which took more than three years to realize, has been turning heads.
However, several versions have been attempted since Leonardo's day, including a few "geigenwerk" keyboards by Japanese harpsichord maker Akio Obuchi.
"This instrument has the characteristics of three we know: the harpsichord, the organ, and the viola da gamba," Zubrzycki was quoted as saying by AFP when he debuted the viola organista at the Academy of Music in Krakow, Poland.
The elegant clavier resembles a baby grand piano on the outside, and features a inscription on the lid. It's a quote by Saint Hildegard, a 12th-century German nun, and reads: "Holy prophets and scholars immersed in the sea of arts both human and divine, dreamt up a multitude of instruments to delight the soul."
Zubrzycki's viola organista has 61 strings inside. But instead of piano-style hammers to strike them, it has four spinning wheels wrapped in horse-tail hair.
Activated by a pedal below the keyboard, these act like a bow on a cello, and create similar sounds.
Check out what Leonardo's viola organista sounds like in the YouTube video below, in which Zubrzycki plays an allegro by the German composer Carl Friedrich Abel.